The Bible Says
Revelation 16:3 Meaning

In Revelation 16:3, the Apostle John reveals the second of seven bowl judgments that will mark God’s final judgments prior to bringing an end to the current age. He describes how the second angel poured out his bowl into the sea, and it became blood like that of a dead man; and every living thing in the sea died (v.3).

This transition from land-based plagues to this judgment upon the sea demonstrates that no part of creation remains untouched when God’s final wrath is poured out. In the ancient world, the sea was both a source of life and a barrier between nations.

The Greek word translated sea means a body of water and context determines what body of water is being referred to. In the New Testament, it primarily refers to either the lake that is the Sea of Galilee or the Mediterranean Sea. This text could apply to the Mediterranean Sea as well, but Revelation 20:13 says “the sea gave up the dead which were in it” which in context appears to apply to the entire earth. Since the judgments of Revelation apply to the entire earth, this statement would appear to apply to all the seas of the earth.

When John speaks of the blood like that of a dead man he might mean any number of things, as a dead person’s blood can be pinkish-red, blue-purple, or greenish-black depending on how long the corpse has been deceased. The main point seems to be that “It looks like death.”

This event is reminiscent of the first plague in Egypt, when the Nile turned to blood (Exodus 7:20-21). However, whereas that earlier plague was limited to one river, now every living thing in the sea dies (v.3). Jesus Himself spoke of an era of massive upheaval in the cosmos that would precede His return:

"There will be signs in sun and moon and stars, and on the earth dismay among nations, in perplexity at the roaring of the sea and the waves, men fainting from fear and the expectation of the things which are coming upon the world; for the powers of the heavens will be shaken.”
(Luke 21:25-26)

We might gain a hint from this statement made by Jesus as to a source of these cataclysmic events on earth, that “the powers of the heavens will be shaken.” From John’s recorded visions we know that the heavenly power structure is being shaken. We saw in Revelation 12:12 that heaven rejoiced because Satan was banned from its premises. In that same passage the inhabitants of the earth are told “Woe” because “the devil has come down to you, having great wrath, because he knows that he has a short time.”

But the physical heaven will also be greatly disturbed. In addition to Jesus’s prediction of this taking place, we saw in Revelation 8:8-12 that there will be great cosmic disturbances. This could affect the tides and/or make a direct impact in a manner that devastates the seas. It appears there will be a combination of natural events and supernatural events that intertwine to bring about this last, final judgement of the earth.